Design and dynamic performance prediction of a novel large-aperture offset-feed deployable antenna

The advancing utilization of space resources necessitates high-performance large-aperture deployable antennas. However, conventional positive-feed parabolic configurations suffer from aperture blockage, existing offset-feed designs often struggle to balance large aperture sizes with adequate structural stiffness. To address this gap, this paper develops a novel design methodology for the large-aperture rib-column deployable antenna configuration with offset-feed reflector. We propose a new offset-feed parabolic surface fitting framework that demonstrates reduced dethroughtion compared to existing approaches, followed by the systemic mechanism design. Subsequently, a tie-rod coupling dynamic model of the antenna structure is developed. This model allows for the analysis and optimization of structural parameters to maximize the fundamental frequency. Additionally, similarity consistency criteria for heterogeneous structural elements are derived via discretization, enabling a robust similitude design method for predicting on-orbit dynamic performance from ground tests. Finally, based on the proposed similitude design method, a 5-meter-diameter scaled-down prototype was fabricated. The prototype deploys smoothly; achieving a repeatability accuracy with a maximum error of -0.99mm, and the prototype’s fundamental frequency is 1.73 Hz. This work provides candidates for large-aperture offset-feed antennas and contributes theoretical reference to the design and analysis of these mechanisms.